Underreamer.



J. rom.

lmnnnnmm. i i .LfUJULTIDl' TILtD JAI. 22, H01. )BILT-'BD LPI. i2. 1900. 905,303.

Panama im` 1, 190s.

. su .on the upper end thereof.

Spaoieatton of Letten; Patent.

retenue Dee. i, 190s.

Application filed January 22, 1907, Ecrial No. 353,431. Renewed April iw, 190B. Serial No. 428,695-

To all whom it muy commi:

Be it known that I, J amies Four, a citizen of the United States, residing :it Los Airgeles, in the county of Los necios and State of California, have inven'ietlnew and useful Improvements in Underreaiiers, of which the followiiinr is a specific ation.

My invention relates to that class of devices by means of which the walls of a well hole may be enlarged below the well-casing; and the object of my invention is to provide a simpl durable and oiective dci-ice therefor haring but. few arts, easily assembled and disassembled und) which are not easily lost in the bottom of the well hole. I accomplish these objects by means of the dcrice described herein and shown in the a'ccompanying drawings in whichz- Figure 1 is a lonfvitudinal section partly in elevation and partly broken away, of my under reamer in its closed or inonerative position inqilnce in the-casing of the well. g.'2 is a like view of my i'eainer in its spread out; or operative position below the end of the casing. Fig. 3 is au elevation of the device removed from the casing showing the mandrel (top broken away) with the cutters secured thereto in their operative position. Fig. 4.- is a transverse section taken on line 4-4 of Fig. 2. Fig. 5- is a perspective view of one of the cutters.

l'n the drawings 1 represents the well rasng and 2 the mandrel to which is secured the cutters 3. These companion cutters, two

'in number, each one like the other are secured nt their upper ends to the cutter rctracting rod 4 by means of the pintle bolt 5 which passes through the holes 24 in the top of the cutters. The retracting rod is held in its elevated position b f iur-ans of the coil spring G, the function o which will be iinderstood by means o the drawings. 'l'liis coiled spring rests upon the annular ring 7 and this ring is held in place in the ringsc curing bolt 8 which )asses through the iinindrel and the ring. he i'orc in this ring is sullciently large to permit the free more nient therein of the i'etractiug rod, butthis rod is lield in place by means of the head 9 This will provide one means (other means being also einployed) to 1prevent the loss of the cutters in the well ho e which occasions great loss and delay when it occurs owing to the difficulty of retrieving the device or parts thereof when lostr in the well hole. Extending trnns rersely through each cutter is :in inverte L-sliaped slot. l0 through which, when the cutters are in place in the mandrel, the cutter securing bolt. l1 passes.

When the cutters are moved into the position shown in Fig. EZ- below the lower end of the casing, the spiral spring will elevate the retracting rod 4 which will carry the cutters upwardly until the securing;r bolt. iasses into the lower leg of the inverted L-s iaped slot l0 and this will cause the cutters to be thrown into their expanded or operative position. When the cutters are in t ieir ex ended or operative position as shown in iig. 2 the shoulder 12 on the cutter will rest. against the shoulder 13 of the mandrel and the shoulder 14 oiithe cutter iwill rest against the main body of the mandrel as at 15 (see F ig. 3). The shoulder 16 on the cutter will rest against and abut the mandrel as at 17. The shoulder 18 on the cutter will abut and rest against the shoulder 19 on the mandrel and the shoulder 20 will abut and rest against the shoulder 2l of the companion cutter. Lugs 2' on the lower und of the mandrel are adapted to project into recesses 3 in the cut.- ters and secure the same against any lateral increment which may be induced by a side preurc against the lower ends of the cutter. As more particularly shown in Fles. 3 and 5 the cutters are interlocking, the l-bwer ends bein wider than the upper ends and overlapping each other. By this construction of the cutters a maximum of material is put into as strong and durable as ossible. Thus it will be seen that the shouh ers on the cutters abutting the mandrel will be such as to give the cutters great strength and rigidity and abundant bearing abutment to cause the cutters to operate firmly and etectively. When power is applied to eleva te the cutters out of the casing t ie shoulder 22 on thc cutters will contact with the lower end. of the well casing und the rod 11 will pass upwardly into the position shown in Fig. l causing the cutters to assume a closed or inoperative stion as shown in Fig. l, when the device can be easily withdrawn from the wel] hole-the con iguratioii of the slot 10 *.fffUNrTEDsn/{r'iss PATENT OFFICE.

JAMES FORT, LS ANGELES, CALIFORNIA, A SSIGNOR OF ONE-HALF TO GEORGE GARTLING, 0F LOS ANGELES, CALIFORNIA.

0im I a minimum of space thus rifiixltinfi,r the cutters f in the cutters 1 11 is forced into the upper end of the ot as it will when the mandrel is drawn out of the seid mandrel,

casing.

the cutters or either of them claim is It will he next to impossible to lose or any part of 'the device in the well hole without breaking the cutter-securing r through each of the cutters and into the man drel on either side thereof and 4inside large enough to prevent 'Having described my invention what 1l which passes this rod can be its breaking.

1. An under reamer comprising a mandrel.,

with recesses therein and siiid i'ovided with lugs on its to fit into said recesses.

' 2. In an under ieamer,

said cutters being provide mandrel beinrIr lower end adapted n mandrel, a plurality of interlochinfr critters at the loweren with recesses therein and said provided recesses and further provided adapted to prevent the upwzir of said mandrel, said cutters being provided mandrel being with lugs adapted to fit into sai( with shoulders d movement of said cutters, and resilient means to hold said cutters in engagement with said shoulders. 3. 1n an under reamer, u hollow mandrel, a 254 plurality of interlocking cutters et the lower c ,g end of suid mandrel, said cutters being pro J vided with recesses therein and said mandrel ,v heilig provided with lugs adapted to enter A said recesses and prevent the transverse 30 movement thereof, and being furthcr-provided with shoulders adapted to preventl the upward movement of said cutters, and sprinv means secured to said cutters whereby seid cutters are retained in position against said 35.' shoulders.

In witness that I claim the foregoing I A have hereunto subscribed my name this 9th f dey of January, 1907.

lVitneSses:

HENRY T. Hrizann, EDMUND A.' b'rimosn.

JAMES Feier. 

